Apparatus and method for packaging a capacitor

ABSTRACT

An electronic device includes a housing ( 20 ) having a first interior region ( 26 ) and a second interior region ( 28 ). The second interior region ( 28 ) is sized to receive an electronic interface ( 18 ). The device also includes a wound capacitor core ( 14 ) adapted for electrical communication with the second interior region ( 28 ), and a capacitor potting material ( 38 ) disposed in contact with the first interior region ( 26 ) and the wound capacitor core ( 14 ).

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application Ser.No. 60/509,018 filed Oct. 6, 2003, which is incorporated herein.

Aspects of this invention relate generally to capacitors, and moreparticularly to an apparatus and method for packaging an energy storagecapacitor, and to an electronic device, and an electronic instrumenthaving an energy storage capacitor.

Energy storage capacitors that include wound capacitor cores, such asmetallized film cores, are typically manufactured as discretecomponents—the wound capacitor cores are surrounded by potting materialsuch as oil or epoxy, and encapsulated using metal or plastic cans, toform complete capacitor assemblies. The complete capacitor assembliesare then assembled into an electronic device, such as a portableexternal defibrillator.

FIG. 1 illustrates two views of an electronic device, an externaldefibrillator, comprising a complete capacitor assembly 2 withprotective metal or plastic can 3. A completed capacitor assembly 2 isgenerally secured into a redundant housing 4, such as molded enclosuresor cradles, within electronic instruments such as externaldefibrillators. In addition, adhesives, pads, support ribs 6 or otherstructures, fasteners, and/or a combination thereof, must generally beused to further secure capacitor assemblies into the electronicinstruments. Because capacitor assemblies account for much of the volumeof many electronic instruments, especially those that require a largestore of high voltage energy, the electronic instruments may requirelarge voids around the support members that cause the instrument to bevolumetrically inefficient. Such voids may compromise the structuralstrength of the capacitor and possibly the instrument itself.

In addition, the assembly of the electronic instrument with apre-manufactured capacitor adds cost to the instrument. The prior artassembly process is also a possible source of defects.

There is therefore a need for an electronic instrument, an electronicdevice, and an apparatus and method for packaging an energy storagecapacitor for use with an electronic instrument, with, among otherthings, increased volumetric efficiency, more reliable assembly, andlower cost.

According to one aspect of the present invention, an apparatus forpackaging an energy storage capacitor is adapted for use with anelectronic instrument. The energy storage capacitor has a wound core,adapted for electrical connection to capacitor interface electronicsassociated with the electronic instrument. The apparatus includes aninterior housing surface having a first region and a second region. Thefirst region is sized to receive the wound core and a potting material,and has a cavity defined by a side surface, a closed first end, and anat least partially open second end. The second region is sized toreceive the capacitor interface electronics. An exterior housing surfaceis arrangeable to at least in part surround the interior housingsurface. When the wound core is disposed in the first region, the woundcore is arranged in such a manner that a void for receiving the pottingmaterial is positioned between the wound core and the side surface, anda conductive path adapted to electrically connect the wound core and thecapacitor interface electronics is arrangeable between the wound coreand the second region.

According to another aspect of the present invention, a method forpackaging an energy storage capacitor is provided. The energy storagecapacitor has a wound core adapted for communication with capacitorinterface electronics associated with an electronic instrument. Themethod includes: providing an interior housing surface having a firstregion and a second region, the first region having a cavity defined bya side surface, a closed first end, and an at least partially opensecond end, the second region sized to receive the capacitor interfaceelectronics; arranging the wound core in the first region in such amanner that a void for receiving the potting material is positionedbetween the wound core and the side surface, and the wound core ispositioned for communication with the capacitor interface electronics,when the capacitor interface electronics are disposed in the secondregion; and depositing the potting material into the void.

According to a further aspect of the present invention, an electronicinstrument includes a housing, and the housing includes a first interiorregion and a second interior region. The first interior region defines afirst cavity and has a configuration defined by a side surface, a closedfirst end an at least partially open second end. The second interiorregion defines a second cavity. The electronic instrument also includesa wound capacitor core, and means for conductively connecting the woundcapacitor core and the second interior region. The wound capacitor coreis arranged in the first interior region in such a manner that a void ispositioned between the wound capacitor core and the side surface. Apotting material is disposed in the void, and a capacitor interface isdisposed in the second interior region, and in communication with thewound capacitor core via the means for conductively connecting the woundcapacitor core and the second interior region.

According to a still further aspect of the present invention, anelectronic device includes a housing having a first interior region anda second interior region. The second interior region is sized to receivean electronic interface. The device also includes a wound capacitor coreadapted for electrical communication with the second interior region,and a capacitor potting material disposed in contact with the firstinterior region and the wound capacitor core. The wound capacitor coremay be shaped substantially similar to and smaller than said firstinterior region.

FIG. 1 illustrates an external defibrillator assembly with a prior artcapacitor component.

FIGS. 2 and 3 are perspective views of an apparatus for packaging anenergy storage capacitor in accordance with certain aspects of thepresent invention.

FIG. 4 is perspective view of an apparatus for packaging an energystorage capacitor in accordance with other aspects of the presentinvention.

FIG. 5 is a flowchart of a method for packaging an energy storagecapacitor in accordance with aspects of the present invention.

Turning now to the drawings, wherein like numerals designate likecomponents, FIG. 2 is an exploded perspective view of an apparatus 10for packaging an energy storage capacitor 12 in accordance with aspectsof the present invention. Energy storage capacitor 12 preferablyincludes a wound core 14, such as a metallized film core. Wound core 14has tab terminals 16 extending therefrom, which are preferably directlyconnectable (for example, by soldering) to capacitor interfaceelectronics 18 (discussed further below). Unlike prior art energystorage capacitors, however, energy storage capacitor 12 forgoes aprotective enclosure, such as can 3 surrounding wound core 14. Instead,aspects of the present invention recognize that can 3 is redundant andspace-consuming, and instead relies on a housing 20 for protection.

Housing 20 includes an interior surface 22 and an exterior surface 24.Exterior surface 24, which is shown in part, preferably at least in partsurrounds interior surface 22 during normal operation of apparatus 10.Interior surface 22 and exterior surface 24 may be made of one or moresuitable materials, such as plastic. Surfaces 22, 24 may be integral—amolded plastic housing, for example—or may be composed of a number ofassembled parts.

Housing 20 has at least two interior regions. Region 26 and region 28are shown in FIG. 2. Region 26 has a cavity, and a rectangular boxconfiguration, defined in part by interior surface 22 and a bottom end32. The top of region 26 is preferably at least partially open, to allowreceipt of wound core 14. Region 26 may also have generally tubularconfiguration, defined, for example, by a circumferential surface that,geometrically, may be a cylindrical configuration or anotherconfiguration.

FIG. 3 depicts a perspective view of apparatus 10 with energy storagecapacitor 12 installed in accordance with aspects of the presentinvention. Wound core 14 is disposed in region 26, with tab terminals 16attached to capacitor interface electronics 18. It is contemplated thatany means for conductively connecting wound core 14 and capacitorinterface electronics/region 28 may be utilized, including but notlimited to leads, pads, or wireless connections, secured to wound core14 and/or capacitor interface electronics/region 28 in any suitablemanner. Substantially any void space remaining between wound core 14 andthe walls defining region 26 is filled with a solid capacitor-protectingsubstance 38, such as an epoxy potting material.

Referring again to FIG. 2, region 28 may be any desirable geometricconfiguration, and may include one or more compartments. As shown,region 28 is a single, substantially rectangular compartment, whichhouses capacitor interface electronics 18. Electronics 18 are preferablyassociated with an external defibrillator, which may be automatic,semi-automatic, or manual, but may be associated with any other type ofelectronic instrument that utilizes energy storage capacitor 12. Oneexample of electronics 18 is a circuit board.

Housing 20, therefore, may ultimately form packaging for an electronicinstrument itself. When capacitor packaging is a part of the electronicinstrument in accordance with aspects of the present invention,redundant capacitor housings such as cans are eliminated, and morecapacitor volume in the electronic instrument is actually used to storeelectrical energy—increasing volumetric efficiency. The end result ofaspects of the present invention is an electronic instrument that may bemade smaller and more rugged, has a decreased need for fasteners andadditional wiring leads, and benefits from simplified and/or lower-costassembly and manufacturing.

Further space utilization efficiencies may be achieved by usingalternative geometric configurations to define region 26. An apparatus100 with a flat-oval configuration is shown in an alternate embodimentof FIG. 4, for example. In this alternate embodiment, wound core 140 isin an oval shape, corresponding to an oval shape of interior region 260.It will be appreciated that a number of geometric configurations ofregion 26 are possible, and such configurations may depend on thecorresponding shape of the wound core 14, or may be independent of theshape of wound core 14.

As shown in FIG. 5, a flowchart showing a method for packaging an energystorage capacitor, such as capacitor 12, having a wound core (forexample, wound core 14) adapted for communication with (for example, viatab terminals 16) capacitor interface electronics, such as electronics18, associated with an electronic instrument such as an externaldefibrillator, begins at step 500, and continues at block 502, where aninterior housing surface, such as surface 22, is provided. Interiorhousing surface includes a first region (region 26, for example) and asecond region (region 28, for example). The first region has a generallyboxlike configuration defined by a side surface, a closed first end, andan at least partially open second end. The first region may be boundedby, for example, surface 22, bottom end 32, and open top end 34. Thesecond region is sized to receive the capacitor interface electronics.At block 504, the wound core is arranged in the first region, so that avoid, such as void 36, is positioned between the wound core and the sidesurface, and the wound core is positioned for communication with thecapacitor interface electronics, when the capacitor interfaceelectronics are disposed in the second region. A potting material, suchas material 38, is deposited into the void, at step 506. The pottingmaterial preferably substantially fills the void, and may be a materiallike oil or epoxy, such materials being well known and widely available.

The embodiment(s) depicted and described herein are meant to beillustrative in nature, and it will be understood that housings of anyshapes and sizes may be designed using the principles set forth herein,and used for various commercial and consumer applications. It will alsobe understood that aspects of the invention are not limited to thespecific embodiments described above, that other and further forms ofthe invention may be devised without departing from the spirit and scopeof the appended claims and their equivalents, and that aspects describedand claimed herein are to be accorded the widest scope consistent withthe principles and features disclosed herein.

1. An apparatus for packaging an energy storage capacitor in an externaldefibrillator, the apparatus comprising: a defibrillator housing havinga first interior region and a second interior region; capacitorinterface electronics located in the second interior region; a woundcore disposed in the first region of the housing and adapted forelectrical connection to the capacitor interface electronics, the woundcore being arranged in such a manner that a void for receiving pottingmaterial is positioned between the wound core and a side surface of thehousing; a conductive path adapted to electrically connect the woundcore in the first region of the housing to the capacitor interfaceelectronics in the second region of the housing; the first region beingsized to receive the wound core and the potting material, and having acavity defined by the side surface, a closed first end, and an at leastpartially open second end, the second region being sized to receive thecapacitor interface electronics; and an exterior housing surfacearrangeable to at least in part surround each of the first and secondinterior regions.
 2. The apparatus according to claim 1, furthercomprising: a potting material substantially filling the void.
 3. Theapparatus according to claim 2, wherein the potting material comprisesone of oil and epoxy.
 4. The apparatus according to claim 1, wherein thehousing and exterior housing surface comprise a molded plastic housing.5. The apparatus according to claim 1, wherein the housing and exteriorhousing surface comprise a plurality of interconnected parts.
 6. Theapparatus according to claim 1, wherein the capacitor interfaceelectronics comprise a circuit board.
 7. The apparatus according toclaim 1, wherein the side surface comprises one of an oval surface, acircular surface and a box-like surface.
 8. A method for packaging theenergy storage capacitor of claim 1, the energy storage capacitor havingthe wound core adapted for communication with the capacitor interfaceelectronics, the method comprising: providing the housing having thefirst region and the second region, the first region having a cavitydefined by the side surface, the closed first end, and the at leastpartially open second end, the second region sized to receive thecapacitor interface electronics; arranging the wound core in the firstregion in such a manner that the void for receiving the potting materialis positioned between the wound core and the side surface, and the woundcore is positioned for communication with the capacitor interfaceelectronics when the capacitor interface electronics are disposed in thesecond region; and depositing the potting material into the void.
 9. Themethod according to claim 8, further comprising: disposing the capacitorinterface electronics in the second region; and establishing electricalcommunication between the wound core and the capacitor interfaceelectronics.
 10. The method according to claim 8, wherein the capacitorinterface electronics comprise a circuit board.
 11. The method accordingto claim 8, wherein the potting material comprises one of oil and epoxy.12. The method according to claim 8, wherein the housing comprises amolded plastic housing.
 13. The method according to claim 8, wherein thehousing comprises a plurality of interconnected plastic parts.
 14. Themethod according to claim 8, wherein the side surface comprises one ofan oval surface, a circular surface and a box-like surface.
 15. Anexternal defibrillator, comprising: a housing comprising: a firstinterior region and a second interior region, the first interior regiondefining a first cavity and having a having a configuration defined by aside surface, a closed first end an at least partially open second end,the second interior region defining a second cavity; a wound capacitorcore arranged in the first interior region in such a manner that a voidis positioned between the wound capacitor core and the side surface; anelectrical path for conductively connecting the wound capacitor core andthe second interior region; a potting material disposed in the void; acapacitor interface disposed in the second interior region, thecapacitor interface in communication with the wound capacitor core viathe electrical path; and an exterior housing surface arrangeable to atleast in part surround each of the first and second interior regions.